The present invention relates to a hub for the rear wheel of a two-wheel vehicle such as a motorcycle, a motor bike, a cycle, that permits reversing the wheel in its support.
Persons using motorcycles regularly reverse the tires of their rear wheel to improve the performance of their vehicle or for economy because of the deterioration of the attack edge of the contour of their tire in the direction of traction. It is thus noted that a rear tire always wears more quickly in the traction direction than in the braking direction. When substantial wear of the tire is noted, the user of the motorcycle reverses it to give better gripping traction because it will then be working in the reverse direction of its preceding wear. However, as the hub of a rear wheel comprises a toothed transmission gear for the movement of rotation, fixed on one side of the hub, and a brake disc fixed on the other side of the hub, the rear wheel must be always mounted in the same position, which is to say with the toothed gear of its hub located on the side of the motorcycle where the drive chain is located. As a result, when the user must reverse the rear tire, he is obliged, after having dismounted the rear wheel, to take the tire off the rim, reverse it, return it into its original position on the rim, and finally remount the wheel. All these operations obviously take a relatively long time.
To this end, there has already been proposed a solution in Japanese patent JP 05 221202 by turning the rear wheel on itself about its axis of vertical symmetry, whilst leaving in place the toothed gear by the transmission of movement from the side of the drive chain and the brake disc on the other side; to do this, it is provided according to this prior art document to dismount the two pieces prior to reversing the wheel on itself, by removing securement bolts that hold them to the central core of the wheel and, naturally, the opposite is done to remount the wheel.
These mounting/dismounting operations of the pieces on the core remain long, difficult and give only a small saving of the time of reversal of the wheel, particularly during competition.
The present invention seeks to overcome this drawback by providing a rear wheel having a hub of simple and reversible design, permitting reversing the rear tire without having to disengage it from the rim of the wheel.
To this end, this rear wheel of a two-wheel vehicle, comprising a hub, a toothed gear for the transmission of rotative movement and a brake disc, is characterized in that the hub is a monobloc assembly symmetrical relative to the transverse medial plane (P) or in three portions easily disassembleable by the nut of the wheel and connected to each other by means rendering them fixed in rotation, which assembly comprises means permitting it in one or the other of its two possible mounting positions opposite each other by 180xc2x0 relative to each other, to have a toothed gear (7; 14, 15) on the side where the transmission chain is located and a brake disc (6, 14b, 15b) on the side where the disc brake is located.
According to one embodiment of the present invention, the hub comprises three parts secured to each other, namely a central hub symmetrical relative to a transverse medial plane, comprising on each of its two front surfaces, a same number of interfitting coupling elements, male or female, distributed in the same way about the axis of the hub, and flanges disposed respectively on the two front surfaces of the hub, one of which carries the brake disc and the other the toothed transmission gear, each of these flanges comprising, on its surface turned toward the associated frontal surface of the hub, complementary coupling elements, female or male, coacting with the coupling elements of the hub to render the hub secure in rotation between its two flanges.
According to a modified embodiment, the hub is symmetrical relative to a transverse medial plane and its two front surfaces are respectively secured to identical toothed transmission gears, the external surface of each toothed transmission gear serving also as the brake disc.